This invention relates to television image size altering apparatus and more particularly, to such apparatus for compressing and/or expanding a television image to derive any desired aspect ratio thereof. In the prior art, different digital techniques have been utilized for altering the size of a television image. Image compression is accomplished with one technique by omitting both horizontal scan lines and picture elements or pixels within horizontal scan lines, as disclosed in U.S. Pat. No. 4,134,128. Because of the omitted signal information however, this technique reduces the picture quality. With another technique, interpolation is performed on the luminance component of the signal between horizontal scan lines and between pixels within horizontal scan lines to either compress or expand the image. However, the picture quality is also reduced for this technique due to the single signal component interpolation and problems due to aliasing or fold-over are possible therewith.